306 research outputs found

    Motor endplate cholinesterase in human skeletal muscle.

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    The activity and properties of cholinesterase (ChE) of the motor endplate and its fractions were studied in isolated human skeletal muscle. This preparation was used since the ChE activity of the membrane preparation was localized only in the motor endplate. The endplate ChE was stable in the isolated membrane for 4 weeks at 4 degrees C. The specific activity of the extracted ChE of human muscle membrane was 29.6% higher than that of the original membrane. Studies with specific substrates and ChE inhibitors indicated that most of the ChE of human muscle membrane and its fractions was acetylcholinesterase, and that the minor component was pseudocholinesterase. A Michaelis-Menten constant of 3.82 mM was estimated in the endplate ChE, and 0.88 mM in the extracted ChE of the endplate. The extracted human endplate ChE was separated into three fractions by Sephadex G-200 chromatography, and into two fractions by acrylamide gel electrophoresis.</p

    Measuring integrated information from the decoding perspective

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    Accumulating evidence indicates that the capacity to integrate information in the brain is a prerequisite for consciousness. Integrated Information Theory (IIT) of consciousness provides a mathematical approach to quantifying the information integrated in a system, called integrated information, Φ\Phi. Integrated information is defined theoretically as the amount of information a system generates as a whole, above and beyond the sum of the amount of information its parts independently generate. IIT predicts that the amount of integrated information in the brain should reflect levels of consciousness. Empirical evaluation of this theory requires computing integrated information from neural data acquired from experiments, although difficulties with using the original measure Φ\Phi precludes such computations. Although some practical measures have been previously proposed, we found that these measures fail to satisfy the theoretical requirements as a measure of integrated information. Measures of integrated information should satisfy the lower and upper bounds as follows: The lower bound of integrated information should be 0 when the system does not generate information (no information) or when the system comprises independent parts (no integration). The upper bound of integrated information is the amount of information generated by the whole system and is realized when the amount of information generated independently by its parts equals to 0. Here we derive the novel practical measure Φ\Phi^* by introducing a concept of mismatched decoding developed from information theory. We show that Φ\Phi^* is properly bounded from below and above, as required, as a measure of integrated information. We derive the analytical expression Φ\Phi^* under the Gaussian assumption, which makes it readily applicable to experimental data

    The relation between visceral adipose tissue accumulation and biochemical tests in university students.

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    We evaluated the visceral adipose tissue accumulation in university students in Okayama prefecture, Japan. Fifty-eight Japanese university students (10 men and 48 women, age 18.4 +/- 0.6 years)were enrolled in this study. Fat distribution was evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography (CT) scanning at umbilical levels. Anthropometric parameters,i.e., height, weight, waist circumference, hip circumference, and body fat percentage; blood examination; and blood pressure (BP) were also measured. In 58 subjects, the V area was 23.4 +/- 21.0 cm(2) and the S area was 122.5 +/- 57.9 cm(2). V areas were significantly correlated with hepatic enzymes, uric acid, triglyceride, and BP in men, while they were weakly correlated with hepatic enzymes, triglyceride, and high density lipoprotein (HDL) cholesterol in women. Correlation coefficients between V areas and clinical parameters were comparatively higher than those between other body composition parameters,i.e., S areas, weight, body mass index (BMI), body fat percentage, and clinical parameters. The present study suggests that visceral adipose tissue accumulation is important for hepatic enzymes, uric acid, triglyceride, and BP in university students.</p

    Cholinesterase of skeletal muscle and its subcellular components.

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    The cholinesterase activity of skeletal muscle and its subcellular components, including motor endplates, was compared chemically in human, mouse and rat. The total cholinesterase activity of muscle per unit protein was in the descending order of human, mouse and rat. Cholinesterase was present in all subcellular components fractionated by differential centrifugation, and was greatest in the microsome fraction followed, in descending order, by the mitochondria, myofibril, and supernatant fractions. Each of these fractions had greater cholinesterase activity in human muscle than in mouse muscle, and in mouse muscle than in rat muscle. The ratio of the activity of the microsome fraction to the activity of muscle homogenate was 11.1 in human, 4.6 in mouse and 3.4 in rat. Because of its relatively greater proportion, the myofibril fraction seems to contribute most to the total cholinesterase activity of muscle. Muscle membrane contained high cholinesterase activity of motor endplates, and the activity was greater than the activity of the microsome fraction in rat. Cholinesterase activity per motor endplate was in the descending order of rat, human and mouse, and the variation was less than the variation in the total muscle cholinesterase activity among these species.</p

    Inhibition of human motor endplate cholinesterase by anticholinesterase compounds.

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    The inhibition of human motor endplate cholinesterase by anticholinesterase compounds was studied using isolated muscle membrane preparation. Ambenonium was most potent, and edrophonium was least potent in inhibiting motor endplate cholinesterase. The slope of the regression line for inhibition of motor endplate cholinesterase was greatest for ambenonium, and smallest for neostigmine and edrophonium. These compounds were less potent inhibitors of plasma cholinesterase. Ambenonium was more specific, and other compounds were less specific inhibitors of motor endplate cholinesterase. In myasthenic patients, these compounds produced adequate inhibition of motor endplate cholinesterase even in the presence of relatively mild plasma cholinesterase inhibition.</p

    Prognostic significance of proliferating cell nuclear antigen (PCNA) expression in non-small cell lung cancer.

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    Formalin-fixed, paraffin-embedded tissue sections of resected tumors from 90 patients were immunohistochemically studied to assess the prognostic value of proliferating cell nuclear antigen (PCNA) expression in non-small cell lung cancer. The individual tumors were classified into groups of high, moderate or low proliferative grade, and 38 (42.2%) patients had a high grade of proliferation. No statistically significant correlations were observed between PCNA grade and TNM status, pathological stage, resectability, histological type, degree of histological differentiation. Only vascular invasion significantly correlated with proliferative grade (p &#60; 0.05). Survival analysis showed that patients with low proliferative grade tumors survived significantly longer (a 5-year survival rate of 83.3%) than those with high proliferative grade tumors (39.4%, p &#60; 0.005). Cox's multivariate analysis revealed that PCNA grade was a significant prognostic determinant of survival. These results suggest that PCNA expression provides an independent prognostic variable for patients with non-small cell lung cancer and that it may be useful to consider this factor in treatment planning.</p

    A METHOD FOR ESTIMATING ELBOW VARUS TORQUE USING ONLY A BASEBALL WITH AN EMBEDDED SENSOR

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    Currently, to measure the elbow varus torque during baseball pitching, it is necessary to attach markers and sensors to the body. The purpose of this study is to develop the method for estimating elbow varus torque by only a baseball with an embedded sensor, and examine the accuracy. Eight baseball pitchers threw a four-seam fastball with maximum effort. The varus torque was estimated using one-link-segment model by an accelerometer and gyro sensor placed in the baseball. The Intraclass Correlation Coefficients between the maximum values of the varus torque calculated by the proposed method and the values calculated by the motion capture system was high (ICC(3,1) = 0.73).This result indicates that proof of concept by one-link model is success and warrants future research to potentially develop a system with greater accuracy

    Neuroradiological and neurofunctional examinations for the patients with 22q11.2 deletion

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    Since neuroradiological features of patients with 22q11.2 deletion syndrome are not well-understood, examinations using functional imaging were performed in this study. Brain magnetic resonance imaging(MRI) and 1H-magnetic resonance spectroscopy(MRS) were performed using a clinical 3-tesla MR imager in 4 patients with 22q11.2 deletion syndrome (2 boys and 2 girls; 2~6 years.) and 20 age- and sex-matched healthy control subjects. Furthermore, interictal 123I- iomazenil (IMZ) single photon emission computed tomography(SPECT) was examined in two of the four patients. Among 4 patients with 22q11.2 deletion syndrome, 2 patients showed polymicrogyria and 1 patient showed agyria. Those patients with brain malformations also showed abnormal brain artery and decreased accumulation of IMZ in 123I-IMZ SPECT. Although all 4 patients showed epileptic discharges in electroencephalogram(EEG), one patient with polymicrogyria had no seizure episode. Decreases in γ-aminobutyric acid(GABA) corresponding to the areas of polymicrogyria and/or epileptic discharges in EEG were shown in all patients except for the patient with agyria. Although consistent evidence was not seen in patients with 22q11.2 deletion syndrome in this study, brain malformations and disturbances of the GABAergic nervous system would be underlying mechanisms of the neurodevelopmental abnormalities in this syndrome

    Evaluation of the GABAergic nervous system in autistic brain : 123I-iomazenil SPECT study

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    Purpose: To evaluate the GABAA receptor in the autistic brain, we performed 123I-IMZ SPECT in patients with ASD. We compared 123I-IMZ SPECT abnormalities in patients who showed intellectual disturbance or focal epileptic discharge on EEG to those in patients without such findings. Subjects and methods: The subjects consisted of 24 patients with ASD (mean age, 7.3±3.5years), including 9 with autistic disorder (mean age, 7.0±3.7years) and 15 with Asperger’s disorder (mean age, 7.5±3.2years). We used 10 non-symptomatic partial epilepsy patients (mean age, 7.8±3.6years) without intellectual delay as a control group. For an objective evaluation of the 123I-IMZ SPECT results, we performed an SEE (Stereotactic Extraction Estimation) analysis to describe the decrease in accumulation in each brain lobule numerically. Results In the comparison of the ASD group and the control group, there was a dramatic decrease in the accumulation of 123I-IMZ in the superior and medial frontal cortex. In the group with intellectual impairment and focal epileptic discharge on EEG, the decrease in accumulation in the superior and medial frontal cortex was greater than that in the group without these findings. Conclusion The present results suggest that disturbance of the GABAergic nervous system may contribute to the pathophysiology and aggravation of ASD, since the accumulation of 123I-IMZ was decreased in the superior and medial frontal cortex, which is considered to be associated with inference of the thoughts, feelings, and intentions of others (Theory of Mind)

    Characteristics of Carbonaceous Aerosols Emitted from Peatland Fire in Riau, Sumatra, Indonesia

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    Biomass burning is a significant source of fine particulate matter (PM 2.5). Forest, bush, and peat fires in Kalimantan and Sumatra, Indonesia are major sources of transboundary haze pollution in Southeast Asia. However, limited data exist regarding the chemical characteristics of aerosols at sources. We conducted intensive field studies in Riau Province, Sumatra, Indonesia, during the peatland fire and non-burning seasons Ni 2012. We characterized PM carbonaceous aerosols emitted from peatland fire based on ground-based source-dominated sampling. PM 2.5 aerosols were collected with two mini-volume samplers using Teflon and quartz fiber filters. Background aerosols were also sampled during the transition period between the non-burning and fire seasons. We analyzed the carbonaceous content (organis carbon (OC) and elemental carbon (EC)) by a thermal optical reflectance utilizing the IMPROVE_A protokol and the major organic components of the aerosols by a gas chromatography/mass spectrometry. PM 2.5 aerosols emitted from peatland fire were observed in high concentrations of 7120 _ 3620 mgm and were primarily composed of OC (71.0 _ 5.11% of PM mass). Levoglucosan exhibited the highest total ion current and was present at concentrations of 464 _ 183 µg m-3. The OC/EC ratios (36.4 _ 9.08), abundances of eight thermally-derived carbon fractions, OC/Levoglucosan ratios (10.6 _ 1.96), and Levoglucosan/Mannosan ratios (10.6 _ 2.03) represent a signature profile that is inherent in peatland fire. These data will be useful in identifying contributions from single bor multiple species in atmospheric aerosol samples collected from peatland fires
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